戊乙醯去氫梔子甘，Penta-acetyl geniposide, (Ac)/sub 5/-GP，分離自梔子果實中去氫梔子甘(Geniposide)，再經乙醯化而來。在過去我們的研究中發現它能抑制培養及老鼠體中增生C6 glioma細胞，本研究發現處理(Ac)/sub 5/-GP於C6 glioma細胞，造成細胞產生凋謝死亡(Apoptosis)，其現象包括染色質聚集，DNA斷裂成180-200 bp之倍數，進一步也發現(Ac)/sub 5/-GP造成細胞週期停止於G/sub 0//G/sub 1/。顯示(Ac)/sub 5/-GP之抗癌作用C6為抑制細胞週期及促進凋謝死亡。進一步研究發現處理(Ac)/sub 5/-GP，增加p53，c-Myc及Bax蛋白表現，且抑制Bcl-2蛋白表現，顯示(Ac)/sub 5/-GP抑制細胞週期及促進凋謝死亡p53，c-Myc與及Bcl-2 family蛋白表現有關，進一步詳細機轉正進行中。
Penta-acaetyl geniposide, (Ac)/sub 5/-GP, was produced by acetylation of a glycoside, isolated from an extract of Gardenia fructus. Previously, we have reported that C6 glioma cells could be inhibited in culturing as well as in bearing rats by treating with (Ac)/sub 5/-GP. In this study, the effect of (Ac)/sub 5/-GP on inducing internucleosomal DNA fragmentation was examined in rat C6 glioma cells. Treatment of C6 glioma cells with the (Ac)/sub 5/-GP caused cell death, chromatin condensation, and internuclesomal DNA ladder. Also, cell cycle arrest at G/sub 0//G/sub 1/ phase revealed that (Ac)/sub 5/-GP induced cell death appears to be mediated by apoptosis. In addition, the results also showed that p53 and c-Myc increased due to treatment of (Ac)/sub 5/-GP in a dose-response and time-dependent manner. Concomitant with the expression of p53 and c-Myc, decreased level of Bcl-2 and increased level of Bax protein were observed. These results suggest that cell death caused by (Ac)/sub 5/-GP through apoptosis and cell cycle arrest at G/sub 0//G/sub 1/ may be associated with the induction of p53, c-Mye and may be mediated with apoptosis-related Bcl-2 family proteins.
